310 



44. Spikes sessile in pairs on a common 



peduncle under each bract 



Spikes not as aboYe 



45. Spikelet singly pedicellate, awnless or 



with a straight or rarely twisted awn 

 Spikelets in twos or threes, one or more 

 pedicellate ; flowering glumes very 

 thin, transparent with a twisted awn 

 or rarely . . . 



46. No glumes outside the bisexual ones ... 

 Outer empty or male glumes 2-3 



47. Spikelets unisexual, ovate 

 Spikelets bisexual, compressed 



48. Outer empty or male glumes 2 

 Outer empty or male glumes 3 



49. Awns 0-2 



Awns 3, flowering glume convolute, 



spikelet narrow 



50. Flowering glume longer than outer ; 



leaves hnear 

 Flowering glume shorter than one or all 

 of the outer or leaves ovate 



51. Spikelets minute, g^o inch 



Spikelets more than ^ inch 



52. Spikelet with a callous base ... 



Spikelet without callous base ... 



53. Spikelets less than f inch long 



Spikelets over ^ inch long 



54. Flowering glumes thicker than outer 



ones... 

 Flowering glumes thinner tlian outer 

 ones... ... ... 



55. Spikelets not articulate on pedicel 

 Spikelets articulate on pedicel 



56. Outer glumes shorter than floweringones 



Outer glumes longer than flowering ones 



57. Flowering glume appendaged at base... 



Flowering glume not appendaged at base 



58. No setae among spikelets 

 Setae present ... 



59. Panicle with sheathing bracts at its 



ramifications 

 Panicle without sheathing bracts at its 

 ramifications 



40. Cymbopogon (p. 



323). 

 39. Andropogon (p. 



322). 



46. 



59. 

 47. 

 48. 



15. Zizania {-p. 317 ). 



17. Leersia (p. 317). 



49. 

 54. 

 50. 



48. Aristida (p. 325). 



53. 



51. 



19. Sphaerocaryum 



(p.- 317). 

 52. 



3. Eriochloa (p. 



313.) 



18. Garnotiai'p.Sn). 



49. Sporobolus (p. 



325). 



16. Oryza (p. 317). 



55. 



56. 



4. Isachne (p. 313). 



57. 

 21. Thysanolaeiia (p. 

 318). 



20. Arundinella (p. 



318). 

 7. Ichnanthus (p. 

 316). 

 58. 

 6. Panicum (p. 314). 

 9. Setaria (p. 316). 



60. 



64. 



